The subject invention relates to gas turbines. More particularly the subject invention relates to cooling of gas turbine components.
A typical gas turbine includes a plurality of combustors arranged in an annular array about a rotatable shaft. The combustors receive a combustible fuel from a fuel supply and compressed air from a compressor that is driven by the shaft. The fuel is combusted in the compressed air within the combustor to produce hot combustion gas. The combustion gas is expanded through a turbine to produce work for driving the shaft. The hot combustion gas is conveyed from the combustors to the turbine by a respective plurality of transition ducts. The hot combustion gas flowing through the transition duct subjects the duct structure to very high temperatures. Typically, cooling is provided to the transition ducts by impingement flow directed from passing airflow through impingement holes at discreet locations in a sleeve enveloping the transition duct. This method, however, is generally effective for cooling the transition duct at the impingement hole locations.